Control valve for work ejectors



, Filed Nov. 19, 1943 v h W Inventor Dna/ h//MTEP Scl/@ER Patented Sept. 25, v1945 inslaan UNITED STATE-S Prt'l'lzlNlT` OFFICE v Y l2,385,733

yCOlIT-ROLVAIAII FOR WORK EJCTORS Paul -Walter Schroom Covington, Ky. `Application November 19, 1943, Serial No. 510,950

` ezcigim'js. '(01. 277-21) This invention -relates to ydevices forejecting work from various typesofmachines, andvhasparticular reference to. an lin'iproved control valve. for controlling the flow ofcompressedqair .toA andthe exhaust of air from the actuating cylinder of :a pressure-operated work ejector. l

The primary .obj ect 4of the present, :invention .is to provide a control valveof Vthe above kind which is simple and durable in construction,eflicient in' operation, andl composed of a minimumv number of moving parts which move short distancesso `as to reduce wear to .a yminimum and ensure along period of usefulness andefliciency for the Valve.

Other objects and specific features of the present invention will become apparent from zthe following description when `considered inconnection! with the accompanying drawing, and the-invention consists in the novel form, combination and arrangement of partsv hereinafter .-more fully 4described, shown in the accompanying `drawing and' claimed.

In the drawing: 'l'

Figure 1 is an enlarged central longitudinal sectional View, partly broken away, of aI controly valve constructed in vaccordance with the .presenti invention; and

Figure 2 is a perspective' .view of the complete valve shown in `ffigure 1. l

Referring in detail to thev drawing, the present control valve includes a cylindrical valve body 5 having closure caps 6 and I threaded on the respective ends thereof, The outer closure cap 6 has a central outwardly projecting portion 6a provided with a cylindrical bore 6b, for a purpose which will later be described.

The valve body 5 has a pair of spaced internal partitions 8 and 9 intermediate the ends thereof, which partitions are centrally apertured and define three chambers I0, I I and I2 Within the body. The partition 8 is provided with a tapered valve seat I3 at its outer side in surrounding relation to its central aperture, and a valve head I4 normally engages this seat and has an outwardly projecting cylindrical guide stem I5 slidably projecting into the bore 6b of the cap extension 6a. A helical compression spring I6 surrounds the stem I5 between the cap 6 and the valve head I4 and acts to normally yieldingly'engage said head I4 with its seat I3. The valve head I4 also has a further inwardly projecting stem I1 that projects axially through the partition 9 and cap 'I, and slidably fitted on this stem I'I is a tubular valve member I8 provided with an intermediate Valve head I9. 'I'he partition 9 is formed at its inner side in surrounding relation to its central aperture witha tapered valve seat 2li-and normally engaged by the valve head I9 through the medium' of a helical compression spring 42.I interposedbetween said Valve head I9 fand the yenlarged inner` end portion-22 of a tappet rod123. The tappet rod 23 is slidably fitted in atubularguide 24 and a tubular axial extension 25 of capv TI, saidguide and the extension 25 being'coupled-bymeans of coupling sleevel 26; -The inner endv of the tappet rod 23 has anaX-ial socketZ-I into which slidably projects the `inner endfportion of the valve stem Il, and the depth of this socket is such that :a clearance is leftjbetweenwthe inner end Awall of the same and` the inner endy of the stemY I1 when the parts arenormally positioned with the valve heads I4 and I-S seated. Thus, when thertapped rod y23 is forced .toward the valvesit has atslight movement before engaging and actuating the stem I.'I to open the valve I4, thereby placing the spring vZI under additional compression for effectively maintaining the valve headl I9 closed.

At itsouter projecting end, the tappet rod 23 is provided with a bifurcated head 28 in which is journaled affroller 29 yadapted'to engage the cam surface of an actua-ting cam, not shown. The .head 28].is preferably amember .separat-e fromthe tappet rod 23 and `1provided ,with ,an axial attaching stem 30 threaded into y.an axial bore provided yin the outer end of the tappet rod 23, as shown in Figure 1.

Communicating with the chamber Ii) at the outer side of the partition 8 is a supply pipe 3l leading from a suitable source of supply of air under pressure, and communicating with the intermediate chamber II provided between partitions 8 and 9 is a pipe 32 adapted to communicate with the actuating cylinder of the work' ejector to be controlled. Still another pipe 33 communicates with the chamber I2 at the inner end of the body 5, and this pipe may extend to a suitable point where it is desired to discharge the spent air into the atmosphere.

In operation, the actuating cam engaging the roller 29 will force the tappet rod 23 inwardly so as to place the spring 2| under additional compression and maintain the valve head I9 tightly seated. As the tappet rod 23 continues its inward movement, the end of the stem I'I engages the inner end wall of the socket 2l and the tappet rod then forces the Valve head I4 away from its seat I3 against the action of the spring I5. When the latter takes place, air under pressure is admitted from the pipe 3| into the chamber I and is allowed to flow through the aperture of the partition 8 in the chamber I I, and then through the pipe 32 to the actuating cylinder of the work ejector. As soon as the ejecting stroke of the ejector has been completed, the tappet rod -23 is allowed to returnl to its norma1 position under the action of the springs I6 and 2|, and as'soon as the inner end wall of the socket 21 starts to move away from the adjacent end of the Valve stem I1, the air., in Vthe pipe 32 and the chamber II is allowed to force the valve I9 open, against the action of the spring 2| so that it will pass through the central aperture ofthe partitionl 9 into the chamber I2 Yand thence through the exhaust-pipe 33 to the atmosphere, thereby permitting the work ejector to return to normal position for its next actuation. This cycle of operation is repeated as longYYY as actuation of the ejector is required. It will be noted that the control valve em; bodies a minimum number of moving parts Which have only relatively slight degrees of movement, th'us ensuring minimum wear of the parts and a long life or periodoi' efoient usefulness for the control valve. It Will, of course, be understood f that minor changes may be made in the details of construction illustrated and described with; out departing from the spirit and scope of the' invention as claimed.

WhatI claim as new is:

l. A control valve for pressure-operatedwork ejectors, comprising a cylindrical valve body having a pair of spaced internal and axially apertured partitions dening three air chambers Within the body, a pair of spring-seated valves seating toward eachother against the respective partitions and normallj7 Vclosing communication 35 between *the end and the intermediate one of saidv chambers, anair pressure ysupply-pipe communieating vwith one end chamber, an air exhaust pipe communicating with therother end charn-` Y ber, a combined supply and exhaust pipe crom-Y ejectors, comprising a spring-seated valve for controlling the ow of air under pressure to the' 'f sure during the period of lost motion between ,the rst-named valve and-said tappet rod.

V3. A control valve for pressure-operated work ejectors, comprising a valve body having a pair of spaced apertured partitions defining two end chambers and an intermediate chamber within Y the valverbody, an air pressure supply pipe communicating with one end chamber, another pipe communicating with the intermediate chamber and'adapted` to communicate with the actuating Y cylinder of the-Work ejector, and a third pipe tubular valve member cooperating with the other l partition for normally closing communication betwee'nthe intermediate chamber and the other end chamber, lsaid rst-named valve having Va stem slidably extending through the secondnamed valve, a cylindrical guide on one end of the. valve body, and a tappet rod slidable in said guide 'and having an axial socket in the inner end 'thereof into which the said valve stem slidably projects, said axial socket of the tappet rod 40 being of a length to, permit limited vlost motion between said tappetV rod and said valve stem, and the seating springlof the second-named valve beingV engaged withv the tappet rod, whereby the tension of the last-named spring will be increased forftightly seating the second-'named' valve during the period of lost motion preceding 4,the opening of the first-named valve. Y

-V PAUL WALTER scHRoER. 

